It's highly unlikely that the United Nations would pass any such treaty in the foreseeable future, and the discussion has been criticized as a time-wasting political maneuver. But the intellectual argument for nature's rights isn't necessarily a patchouli-soaked Gaia fantasy translated into legalese. Some say it's a practical extension of ecological insight.

"It has to happen. We have to be able to give legal protection and consideration to the rest of the natural world," said Patricia Siemen, executive director of the Center for Earth Jurisprudence. "It's in the human best interest, as well as the larger natural world's."

The first principle of Bolivia's law – here translated into English (.pdf) from the original Spanish – calls for human activities to "achieve dynamic balance with the cycles and processes inherent in Mother Earth," with Mother Earth defined as "a unique, indivisible, self-regulating community of interrelated beings that sustains, contains and reproduces all beings." A ministry of Mother Earth will be established, and an ombudsman appointed to hear disputes.

In the United States, the idea of legal rights for nature was planted by a 1972 article in the Southern California Law Review, entitled "Should Trees Have Standing?" (.pdf). Its author, University of Southern California law professor Christopher Stone, noted that established legal traditions recognized many non-human entities, from corporations to ships, as full-fledged people for legal purposes.

"To say that the natural environment should have rights is not to say anything as silly as that no one should be allowed to cut down a tree," wrote Stone. But in his view, it was just as silly to think humans had inalienable rights to destroy communal entities like streams and forests. He proposed that people be allowed to claim guardianship of threatened natural resources, much as family or friends become guardians of loved ones unable to represent their own interests.

Stone's claim would ultimately influence Supreme Court justice William O. Douglas, who in his dissent in Sierra Club v. Morton called for legal recognition of "valleys, alpine meadows, rivers, lakes, estuaries, beaches, ridges, groves of trees, swampland, or even air that feels the destructive pressures of modern technology and modern life."

"Each time there is a movement to confer rights onto some new 'entity,' the proposal is bound to sound odd or frightening or laughable," wrote Stone. "This is partly because until the rightless thing receives its rights, we cannot see it as anything but a thing for the use of us."